Re: CREATE INDEX CONCURRENTLY on partitioned index

Hi,

I think it's well worth the effort to revive the patch, so I rebased it
on master, updated it and will return it back to the commitfest.
Alexander, Justin feel free to add yourselves as authors

On 29.01.2024 12:43, Alexander Pyhalov wrote:
> Hi.
>
> I've rebased patch on master and it'seems to me there's one more issue -
>
> when we call DefineIndexConcurrentInternal() in partitioned case, it
> waits for transactions, locking tableId, not tabrelid - heaprelid
> LockRelId is constructed for parent index relation, not for child
> index relation.
>
> Attaching fixed version.
>
> Also I'm not sure what to do with locking of child relations. If we
> don't do anything, you can drop one of the partitioned table childs
> while CIC is in progress, and get error
>
> ERROR:  cache lookup failed for index 16399
I agree that we need to do something about it, in particular, I think we
should lock all the partitions inside the transaction that builds the
catalog entries. Fixed this in the new version.
> If you try to lock all child tables in CIC session, you'll get deadlocks.

Do you mean the deadlock between the transaction that drops a partition
and the transaction doing CIC? I think this is unavoidable and can be
reproduced even without partitioning.

Also not sure why a list of children relation was obtained with
ShareLock that CIC is supposed to avoid not to block writes, changed
that to ShareUpdateExclusive.

Regards,

Ilya